Saturday, April 21, 2012

TitanFlex Ultegra Di2

I am a low-wattage athlete.  Maybe 150 watts continuous, tops, and that's with some of the best coaching and training available.  Much of this is due to my low ability to absorb oxygen: The most important and overworked muscle in most of my workouts is my diaphragm.

So I'm always looking for ways to get the most out of what I've got.  In the swim, I use the Vance method: Very long, powerful strokes, emphasizing precise form, combined with breathing on every stroke.  On the run, I wear the lightest shoes I can find that are also comfortable and don't interfere with my gait.

Then there's the bike.  I'm not able to do much grinding: The oxygen needed to support long, deep muscle contractions quickly outstrips my ability to provide it.  So I favor lots of quick, short contractions, which means I'm a "spinner": I maintain a high cadence that's able to produce good power (for me) over a fairly wide range (85-115 rpm).  I need lots of gears to make the best use of my limited power production, and that means I'm always shifting.

I've compared myself with other riders, and I think I shift about twice as often as most.  I'm really amazed by folks who forget to downshift at a stop light, and are able to pull away and get back up to speed using a single gear.  When that happens to me, I need to push away with my foot, and hope I have enough speed to downshift.

Shifting to always be in precisely the right gear is a priority with me, since missed shifts cost me so much.  Downshifting is my greatest challenge: I've broken two chains over the past 4 years due to approaching a steep hill with lots of speed, and not being able to get into my granny gears fast enough, needing to apply power before the final shift completed in order to avoid coming to a complete stop.  A broken chain definitely makes you stop.

Part of the problem was having so many gears to shift through: I'm one of the few triathletes I know who rides with a triple in front.  Switching from a fast descent to a steep hill means I may need to drop 29 speeds!  Of course, I don't visit each one individually, but I do need to shift through 2 in the front and 9 in the rear.  That's lots of wrist motion!  And that takes lots of time, which I often run out of when I don't start downshifting early enough.

But that's not the worst: On a long ride with gentle rolling hills, I'm shifting many times each minute.  By the end of a long ride, my wrists can hurt more than my legs.

I want to make each shift quicker, and also make multiple shifts easier.  I could do wrist exercises, but I'd rather rely on technology, and that means electronic shifting.  I dreamed about getting the Shimano Dura Ace Di2 when it came out, but the price of the upgrade would mean I'd need to stop spending money on things like food.

When the rumors of an Ultegra Di2 were confirmed and samples of the new gruppo, the Shimano Ultegra 6770 Di2, were shown, I was glad I waited: The electronics technology in the new Ultegra Di2 is more advanced than that in the Dura Ace Di2 (slim 2-conductor cables vs. bulky 5-conductor cables), though the mechanical technology is a bit simpler (larger, heavier) but no less capable.

The downside is that Ultegra Di2 and Dura Ace Di2 electronics don't mix:  You can't, for example, use a Dura Ace derailleur with an Ultegra shifter.  But that may change next year: Dura Ace will be switching to the Ultegra cabling system, though it remains to be seen if Shimano will use the same connectors and signaling to permit components to be mixed.

Best of all, the Shimano Ultegra Di2 gruppo costs the same as the Dura Ace mechanical gruppo!  With such a large price advantage, my next step was to talk with my bike's creator, Tom Piszkin (prolific inventor, owner of AIRO-Series,  former TCSD President, current TCSD Sponsor and Winter Track Coach, and the list goes on) to determine what it would take to upgrade my TitanFlex Al-Ti bike from my current Ultegra triple to a compact Ultegra Di2.

My first concern was going from 30 gears down to 'only' 20:  To keep my lowest granny gear, we'd need to go with the smallest front chainrings the Ultegra Di2 supports (50-34), along with the widest-range cassette (11-28) in order to keep a decent (but lower) high-end.  Well, aside from steep descents, I seldom used my top gear, so that's not much of a loss.

Another factor was the distance between gears: The steps between gears would be about 50% larger.  So if a single gear change at fixed speed on my triple caused a cadence change of 6-7 RPM, I could expect my new compact gears to cause about a 10 RPM change.  That's quite a difference, but I decided it should be compatible with my spin range, though I'd need to work on widening it even further.

After several email exchanges with Tom, we decided the TitanFlex looked to be an ideal Di2 platform, and that the risk of problems was minimal.  Tom had been wanting to make a TitanFlex Di2 for some time, but there was no way he could justify equipping a demo bike with Di2, and no customer had yet ordered one.  So Tom made me a very sweet deal to be his prototype Di2 installation, with the agreement that I would work with him to perfect the installation over time.  And I also had to do as much of the teardown and cleanup as possible before I delivered the bike.

Tom started working on the bike last Thursday, April 20th, and I picked it up the next day.  Talk about quick work!  But there was a hitch: Tom had done all the mechanical work, and since I'm an engineer, he wanted me to do the electronic adjustments.  Our agreement was indeed a partnership on this project.

However, considering that I had previously never been able to make my own derailleur adjustments, I did have some concerns.  Fortunately, the Shimano instructions, though limited, provided the information I needed.  But it was dark by the time I finished last night, so I was unable to take a test ride to make sure I did it right.

This morning I took my TitanFlex Di2 to the TCSD Saturday Ride.  I thought it would be wise to do my first ride surrounded by experienced folks, just in case I got myself into trouble and needed advice.  Best of all, Brian Long had offered to lead a slower group: Did I mention I haven't ridden my bike much since last season ended?  Yeah, I definitely needed a slower group.

Once we started on the coastal ride, I immediately had trouble shifting - the shift buttons felt very stiff.  Well, not really:  It turned out that I was used to combining force with motion on my old shifters.  The new shifter buttons moved only about 1\4", so I instinctively used much less force.  Once I corrected for this, shifting was positive, consistent, and effortless.

And the shifting was quiet:  A rapid but faint click-buzz-snick was the sound I heard, and the shift was completed before I could get my finger off the button.  Evidently, I hadn't screwed up the adjustments.  When we came to our first mild positive grade I intentionally delayed shifting until I was just starting to struggle, then quickly shifted to the right gear.  I would estimate the process was about 20% faster than the best I ever did with my mechanical cable shifters.

Another neat feature was the complete absence of chain-rub against the front derailleur:  As you switch rear sprockets, the system automatically moves the front derailleur as needed to keep clear of the chain.  That's a nice touch that I really appreciate, especially when I'm in aero and don't want take an arm out only to adjust away the noise.

When we came to the flat at the top of the grade I dropped into my clip-on aero bars and proceeded to accelerate.  As those of you who have them know well, shifting while in aero with clip-on aero bars is not a simple process: You must take an arm out of aero and reach over to the brake-shifters in order to change gears.  And you can only do one side at a time: A combination shift means coming out of aero, doing the shift, then returning.

For single shifts, the buttons made a huge difference for me: Much less wrist motion and shorter contact with the button meant my arm was back in aero a bit sooner.

I tested several shifting situations on the way to the Carlsbad Starbucks, though none of them included any serious climbs or descents.  But soon after leaving the Starbucks and starting back, I realized my experiments on the way up and my time away from riding had combined to yield some serious bonking.  My power had diminished greatly, as had my ability to spin effectively.

It was also at this point that I realized I had completely forgotten to bring water with me.  I was so focused on getting the bike ready that I had forgotten that one small detail.  Sure, I could stop at a store and buy some, but I decided to see how well my new gears worked while I was wimped-out.

The ride back went well: The increased distance between gears was not a significant issue.  I spent every moment I could in aero to reduce the effort required, and every shift was quick and clean, which was not always the case for me when riding bonked on my prior system.

Then came that last rise into Del Mar, and my legs informed me that 29.8 miles was just the distance they needed to complete their transformation from flesh into lead.  Despite being tired, the shift into my granny gear was delightfully quick, and the ratio was just what I needed to creep up the hill at a stately 6.5 mph.

So, that's the story and the review.  Now for the pictures!  Here's a shot of the whole bike (click to enlarge):

Not much is noticeably different at this distance.  The new Ultegra finish is a bit darker than that of my prior gruppo, the brakes from which I kept to reduce cost

The rear electric derailleur is a bit larger and chunkier than it's cabled sibling, but not massively so.  Rather than use the wire covers recommended by Shimano, Tom instead chose to use a transparent chain-slap guard: It disappears if you aren't looking for it, and doesn't hide my beautiful hologram-effect paint.

The front derailleur is huge!  My rear brake was a compact model that used to fit below the upper stay: I had to switch back to my prior Ultegra brake to make room for the new derailleur.  Notice also the gorgeous finish of the crank and chainring: Shimano is really stepping up the beauty factor.

Yes, I did keep my trusty Shimano STB pedals: They do everything I need them to do and more, for a small fraction of the cost of other pedals.  They're part of the reason I was able to afford this wonderful upgrade in the first place!

The front view of the shifter: No more shifter cable coming out the top!  They also are much narrower than what they replaced.  Taken together, my cockpit is more open and much less cluttered.

The side view:  There are two buttons, one textured and one smooth.  The brake handle doesn't move side-to-side, and also serves to protect the buttons.

The combination status display and cable junction (two shifter button cables to one frame cable).  The display shows the battery level if any shift button is held for over half a second.  It has other functions used during system configuration.

Why is this picture here?  Yes, those are my clip-on aero bars.  They are also where I will mount the remote shifter buttons Shimano will be releasing in the next 6-9 months.  You heard me right!  Coming soon to a bike near me: Clip-on aero bars with remote shifters!  Woo-hoo!

That's the tour!  You've seen everything, right?  Well, those of you who've also drooled over Di2 will have noticed there's one component missing: Where's the battery? Where is that bloated black blob that ruins the appearance of almost every Di2 bike in existence?

This is why you want a true inventor, and the creator of your bike, to do your Di2 installation:  Tom hid the battery just in front of the rear wheel.  It is masked from one side by the front derailleur, and from the other side by the frame fairing.  Here's a look from the top:  That's the rear wheel on the left, and the front derailleur on the right.

Sorry for the over-exposure, but it's dark back there and I had to use the flash.  The battery is mounted vertically, and when released drops down from the bottom of the frame.  You can see the corner of the battery peeking below the chainstay in the next photo.  It's also partly covered by the chainring.

One note about the battery:  While Shimano doesn't specify the number of shifts per charge, I've been able to figure out from several sources that I shouldn't need to charge the battery more than 3-4 times each year.

Now you've seen it all. But there's still one question to answer: Was it worth the price?

Sure, I always like new shiny things that encourage me to train more.  Heck, I just like them anyway.  But this was absolutely a major investment for me: Does the performance justify the expense?

I must admit that I do miss the tight grouping of the gears on my triple.  I would have loved it if Shimano had made a triple version of the Ultegra Di2.  But since I did fine on my first ride despite bonking, I don't think it's really much of an issue: Just something to get used to.

The system has met every one of my expectations, and I made sure that I had realistic expectations right from the start.  I suppose the lack of surprises was one of the best surprises!  Shimano delivered everything they promised, and the features I wanted most were demonstrated and proven.

So, yes, at this early point the system seems worth it.  We'll see if that changes once I ride more miles and complete some races.

One thing for sure:  The TitanFlex is an ideal Di2 platform.  Tom will soon be updating the TitanFlex web site to include an Ultegra Di2 option, and I expect that bike will represent an ideal combination of technology and function.

I know mine does!